Paul Yates from Intelligent Fingerprinting, a company spun out from the University of East Anglia in Norwich, and colleagues, have developed a handheld device that police can use to detect breakdown products from drugs excreted through sweat pores in the fingertips.
The device applies gold nanoparticles coated with antibodies to a fingerprint. The antibodies stick to antigens on specific metabolites in the fingerprint. Fluorescent dyes attached to the antibodies will highlight the presence of any metabolites. The technique was first used to detect nicotine, but now works on a range of drugs, including cocaine, methadone and cannabis.This has some positive applications. If administered properly, it can prove that someone is not currently driving under the influence, which paves the way for identifying that and freeing up the drug test to deal with a person's current state. This has been a major (and rightly so) point with anti-marijuana camps. Right now if you fail a marijuana test you can be considered under the influence, which is ridiculous because the component they test for can remain in the body for up to six weeks. It would add a risk component to casual drug users who are tempted to drive, and if the courts handle those cases correctly we could have a proper deterrent.
Of course, reality implies it will be used to coerce and intimidate, but a girl can hope.